Arthur Hemmendinger died on June 17, 2012, at the Good Shepherd Hospice House in Manhattan, KS. He was born on July 11, 1912 in Bernardsville, NJ, the son of Max and Jeannette Harris Hemmendinger. Afflicted with polio in one leg as a child, from which he eventually recovered completely, Art spent much of his boyhood in his family's basement building radios. After graduating from Bernardsville High School, he entered Cornell University with an interest in electrical engineering. Following his graduation from Cornell, Art earned a PhD in experimental physics at the California Institute of Technology where he used a mass spectrometer to make the first accurate measurement of the abundance (about 0.01%) of the naturally occurring radioactive isotope of potassium. Art then joined the faculty of the University of Oklahoma, where he taught for four years as an Assistant Professor of Physics. Eager to contribute to the war effort, he left Oklahoma and teaching in 1941 to work for the Naval Ordinance Laboratory in Washington, DC, where he met his future wife. On a barge in Chesapeake, he helped develop sonar detonators for underwater mines and torpedoes, as well as a device that was used successfully to save many seamen's lives by detonating torpedoes fired by German U boats before they reached targeted American naval transport ships in the North Atlantic. A new opportunity arose in 1945, and he was hired to work on what he soon learned was the Manhattan Project to build the first atomic bombs. He was initially sent to Enrico Fermi's laboratory at the University of Chicago, after which he returned briefly to New Jersey to marry Peggy (Margaret Elaine Ross), who by then was working at Bell Laboratories in Summit, NJ. Their honeymoon was a one-way journey, first to Chicago and then to Los Alamos, NM. They both became enchanted with the mountain Southwest, and Art continued as a staff member at the Los Alamos National Laboratory until his retirement in 1977.There his work contributed to thermonuclear weapon design, based on experiments using a Van de Graaff electrostatic accelerator, and later when he measured neutron emissions from underground nuclear explosions conducted in the Nevada desert. During their 24 years living in Los Alamos, Art and Peggy raised their three children, Ross, Anna and Dennis. Art was active in the local ski club, sharpening axes and saws that volunteers used to cut timber to clear slopes. He also served for several years as the Los Alamos Democratic County Chairman. In 1969, Art and Peggy purchased a hill top home in Santa Fe, NM, where scores of people enjoyed their generous hospitality. During their 38 years in Santa Fe, until the age of 92, Art regularly enjoyed skiing, playing tennis and repairing tape recorders for the blind at the State library. In 2007 Art and Peggy moved to the Meadowlark Hills retirement community in Manhattan, KS, where Peggy died six weeks later. Until recently, Art enjoyed playing bridge at the Manhattan Senior Center, reading, and shooting occasional games of pool at the Meadowlark billiard table. Art was also predeceased by his brother Henry and son-in-law John Chamberlin. He is survived by his brother Noel in Alexandria, VA; Art's children, Ross (Barbara) in Williamsport, PA; Anna in Waterloo, Ontario; Dennis (Sue Maes), in Manhattan, KS. Other survivors include four grandchildren - Joshua (Cathy) Hemmendinger, Wendy (Zeak) Johnson, Matt Hemmendinger, and Claire (Aaron) Lindh - and three great-grandchildren. Art's last years were enriched by the special care of Dr. Doug Hinken and the loving care of providers at Meadowlark Hills and, more recently, at the Good Shepherd Hospice House. A family memorial gathering will be held at a later date. In lieu of flowers, contributions may be made to Meadowlark Hills Foundation, 2121 Meadowlark Rd., Manhattan KS 66502; the Manhattan Senior Center, 412 Leavenworth St., Manhattan KS 66502; or Good Shepherd Hospice House, 3801 Vanesta Dr., Manhattan, KS 66503. Online condolences may be left through the Yorgensen-Meloan-Londeen Funeral Home website at www.ymlfuneralhome.com. The Yorgensen-Meloan-Londeen Funeral Home, 1616 Poyntz Avenue, Manhattan, KS 66502, is handling local arrangements.